Right now I am into Ingress. You have to actually visit locations and compete against another faction. I find it interesting.

Many of my colleagues are also into Marvel Future Fight.

I'm a bit fan of ingress too.  I play for the Enlightened Faction. It's a good location based game that is quite engaging.

For very engrossing armchair game, take a look at https://www.youtube.com/watch?v=D_2zoYSsBz4.  Be warned that this is a walkthrough of chapter one which is a guided training exercise. You won't spoil much by watching.  Although the video is of a PC version, the sound and graphics are every bit as good on a phone.  Available for iPhone and Android. the Room and The Room 2 are available now.  The Room three is expected to be released any time now.

For Board games; Catan and Ticket to Ride are both good; or if you have big enough tablet / phablet, try the online version of Cards Against Humanity (it's a browser game)

for RPGs; indeed, Square has a lot of games– the retro ones at least. FF5, FF6, FF4... Although the price is quite much, it's definitely worth the price. For a cheaper, more free(mium) game; I suggest trying Final Fantasy Record Keeper; it's all the battles without the exploring, with a freaking lot of your beloved FF chars.

But other freemium games from Japan seems to have its fanbase too. I dunno about the pay-to-win aspect of it though...

Ingress is good if you like to walk or travel.

ANd I'm sure there's a lot of other games too >_< Pixel Dungeon is a HARD Roguelike game, but if you like a challenge; do try.

Many of my colleagues are also into Marvel Future Fight.

Also, I haven't played it, but I know for sure that some Final Fantasy games are available as well. It doesn't get any better than that