Here are some TapJoys I’ve done:
Gratorama (basically sign up at some poopy Casino and spin your free spins) I DID NOT GET MY REWARD FOR THIS YET. Still waiting. It’s supposed to be over 1000 gold.
Kobo (sign up, make a PURCHASE, download app and read your purchased book) I DID NOT GET MY REWARD FOR THIS and I contacted TapJoy 10 days ago and sent follow ups to my ticket 2 times - no reply from them. Going to ask Kobo for a refund even though it was only half a dollar. Was supposed to generate 400+ gold. Avoid this.
Portal Quest (install and reach team level 10) I completed this in 20-30 minutes and it generated 72 gold. Good deal. The game pretty much plays itself and it’s colourful and fun to watch.
Lords Mobile (you’re gonna have to play for a while but it’s do-able, you have to upgrade your city until you reach a certain level - then research level 2 monsters) I did this in 3-4 days or so. Got my 443 gold.