Google Chrome! Hands down. This is the MOST used application on my Android phone ever! I use the web-browser constantly for research, reading, entertainment (videos occasionally). I even use it for work related activities. Second to perhaps phone calls and texts (primarily work related), but I believe we can disregard those as "apps" to be discussed (basic, plain, functional and needing no improvement; Other than perhaps a better built-in "spam guard?").
The "2nd" runner up app I use would be #AndChat (IRC client that was *very recently* discontinued from Google Play Store). It's equally plain, but supports multiple tabs, SASL, SSL, proxies (if you prefer) and more. I've been fairly inactive on freenode for the past year. I heard AndroIRC's pretty good though! It's latest update makes it 'tolerable.'
The only other major time consuming activity I use on my phone would be the only video game I really play anymore (and after ~3yrs have ALMOST beat); Boom Beach! The graphics are EXCELLENT! I disable audio, obviously. The game-play (free to play at that) is phenomenal.
PS: First post!
