Yes it's free to play with in app purchases of course. And okay I will write a description, but I think I'm gonna try and section it off.

First and most important is battle as you cannot use voice over at all in battle. The battle screen looks something like this.
Starting from the bottom left right hand corner of your screen right above the home button is attack, then 1 to the right of that is defend, then ability 1, then ability 2, and lastly your soul break when you build it up. Then right above those button are 3 more starting from the far left you have an auto attack which allows you to just press that once and your characters will attack without you having to constantly hit attack your self, works good when your not in a boss fight. The next one to the right of that button the just added, it's the roaming warriors button we'll just call it. That button allows you to use the soul break of another players character and I believe it can be used twice per dungeon. Then you skip some screen and right above your soul break button is the player turn skip button which is pretty self-explanitory.
The third row of buttons is your enemies and the number just depends on how many enemies you happen to be fighting, basically how that works is you can instead of just hitting attack, touch one of the enemies on the screen and then hit attack and you will attack the target you selected. Note that the enemies go from left to right to almost the right edge of the screen which brings me to my next set of buttons.
On the right hand side of your screen above the player turn skip button are your characters, really you won't probably ever be targeting your own guys but it's still worth mentioning. Obviously without voiceover you can't see your hp or anything so how I have been playing is a pure power team using guys with high hp and high attack and defense so I don't need to cure anyways. Besides you get potions and stuff for killing enemies.
For boss strategies and stuff I just go to the ffrk wikia that they have which gets updated quite frequently. Most of the time if you can't beat the boss though either you need to level up more or it's just impossible to beat with out having maxed relic gear which is not easy to get.
Also I should note when you first start the game it will have you go in to a battle and you will need to turn off voiceover to do that part, and just tap on the middle of the screen above the home button to skip through the talking. The rest you can probably figure out.
Oh one more thing, the victory screen. Basically all you do is press on the middle of the screen either right above the home button or a little ways above that, sometimes it changes depending on the items you are recieving. Doind this scrolls first past the rating screen, hten the exp screen then the items you recieved screen all in the victory screen, once you have done that it takes you back to the dungeon and you can turn on voice over and continue from their.
Sorry about my grammar and if I haven't explained something thoroughly enough or I left anything out let me know.

Ah yes, sometimes when you start the game the screen does not fully load. just double tap on the system error a couple times and then tap anywhere on the screen and start flicking right. until you get to play.
Also I should mention that sometimes it likes to lock up on you and not let you move anywhere. When it does this you need to close the app and restart it and it will work.

that brings me to my next section of how to play this. selecting a dungeon.
Basically it works like this, all the dungeons are doors that you click on, to move between these doors you have to shut voice over off, then take your finger and slide it either from left to right, or right to left depending on which way your trying to go. Your finger should be about half way up the screen and you should start from the left edge and swipe twards the middle or the right edge and swipe towards the middle the bigger your swipe the more it moves the screen. It takes a bit of getting used to.
Also on the main screen their are event dungeons, to access those you need to touch like right below where your ear piece for your phone is. If you go to far to the right you will touch the quests button instead. Which to go back at any time you just need to touch the bottom left hand part of your screen where the attack button would be if you were in battle. Once you press the event dungeons button you can turn back on voice over and select which event you would like to enter and then pick your dungeon.
Lol the more I write the more I realize how complicated it is to play this.

Thank you for this.I am downloading this now, so will let you know if I have any questions 

Yes, I  if it's possible, can you explain all the beggining?

OK, so I've just beaten the first dungeon and now I'm stuck. I've been told to add the black and white mage to my party, but clicking any of the options just brings up that dialog again. What do I do?

Okay I did some thinking and remembering, in the tutorial to skip through the talking with voice over on you can double tap on the text, to add members to your party you need to click on the world link with voice over on, I know that sounds strange but it brings up the party screen. Use your router to change the navigation to headings, tap anywhere on the screen flick once to the right and then flick down. From that point flick left until you get to the word party, and double tap. If for any reason it says heading not found then that means the screen did not load all the way, just double tap on any of the stuff at the top I usually do it on the mythril or gil. Once you double tap on party it will bring up 4 options, 2 of which are going to be relevant for any starter and that is change party members, and growth eggs. double tap on change party members, and then to ad a member you double tap on the cash image and it will select them.
I just remember an easier way for now, at the main screen before you click on party their should be 3 items to the right of the heading you go to, and that is optimise confirm and undo. Press optomise and then confirm and it should automatically add them to your party. I will write up on how to equip abilities and gear soon.

Hmm, any idea on how to use growth eggs? I have a ton of them now and have no way to use them, since clicking the plus button does nothing to add to the counter. Strange.

Okay, to summon a romaing warrior all you have to do is select them from the list the top one should already be selected, this happens after the screen where you hit enter dungeon and it shows you your party. Hit next then the roaming warriors screen should pop up. Navigate by headings and scroll down til you hear romaing warriors, and then just make sure the top one is selected you can tell cause it will say deselect for the option instead of select.
To use growth eggs, you have to try and tap along the right hand corner of the screen, with voice over off, you will eventually find the plus buttons, but don't go up too high or you will start clicking on your party members, I would say a safe bet  is to not touch the top eighth to quarter of your phone. Anything below that portion of your screen touch, but stay along the right edge, sometimes maybe try going just a little ways in I have trouble finding those buttons sometimes, so I usually wait til I have a ton of eggs. then use them on one character and boost the level, They just added memory crystals to break the level cap so I usually save it for those characters. Also for you new guys you might wanna accept some of the quests as they go right along with what your doing. Just keep asking questions cause then I know at least where to start explaining this stuff, sorry I'm not that good at explaining how to play games lol.
you need to probably upgrade and combine your equipment to not get raped by bosses. it's kinda tricky to do but it's easy once you get the hang of it, click on equipment under party, then click ready equipment and scroll down til you hear current party, then click on the first cash image in the list, this will bring up the first person in your party and show you what they are wearing and also most importantly it shortens the list of cash images to just the 5 people in your party so you can switch between them and equip them with stuff. I'm telling you this first because to upgrade your equipment you need to first know what you are wearing.
Once you find that out hit back or just click party and back out that way and go back to the equipment screen and this time hit upgrade.
From that screen you wil see a list of a bunch of cash images followed by a level, 1/3 or 1/5 or something. that's your equipment, and to upgrade it you simply click on a cash images then scroll down past the list of stuff, the heading navigation will take you right past it. Flick right until you hear the name and after it will say E and the person who is wearing it. To upgrade it you simply select items from the list by hitting the cash image by the level, but it's a good idea to use the awsome sort features that I just recently figured out. if you flick down in heading mode you will find a heading that say select type if you flick left from that their is a combo box. Double tap in to that combo box and flick down til you hear weapon upgrade or armor upgrade depending on what you are trying to upgrade. Then it will put your weapon or armor upgrade materials first in that list and all you have to do is go down the list clicking on each one, note however that when you organize that way it putts either weapon before armor upgrade materials or vice versa so you will eventually be using armor upgrade materials on your weapons or vice versa it can't be helped but don't freak out because it doesn't really matter it's just you only get half exp for using a armor upgrade mat on a weapon or the other way around.
Their is also a combo box like that on the first screen where you actually select the weapon to be upgraded, you can change between all the ff's by number or whatever even by rarity, the higher the rarity the more levels it has, 5 star rarity items have up to 20 levels, and can be combined twice to make a max of level 30. And everything I just explained for equipment works the same with abilitys as well, the only real pain in the ass with abilitys is honing because the game like to jump you around the screen sometimes when your trying to navigate and it will make you start over from the top of the screen. it does that a lot in equipment when you get max level gear so be warned, my solution to it is to just try and flick through your abilities or gear really fast.

Okay to do relics, click on the party link, it will bring up the relics screen, navigate by headings and flick down once I believe and then left, and you should hear cash image, list end. Double tap on that and it will bring up a screen that talks about relics, from the top of the screen flick right until you hear 1 free draw, and double tap on that. it will start a draw process, when you hear the ding sound like it gave you an item, flick right and doubple tap on the mythrill or the gil and it will make that relic draw screen go away and you can see what you got for your relic draw. And that should hopefully complete that part of the tutorial.
I want to mention that if you listen good you can hear a ding if you count those and you hear more then 1 ify ou hear like 3 or more that's a good item, if you hear 5 and like some awsome sounding music that means you got a weapon with a soul break usually those weapons are character specific, but they are uber powerful and super rare Not to mention the added bad ass soul break that usually comes with it.