What are some good, non-battery-draining iPhone/iPod Touch games?

Keeping the screen on is what uses most of the power.

Not a game, not free, and takes up a ton of storage - but https://itunes.apple.com/us/app/wiki-offline-wikipedia-experience/id378348813?mt=8 is good for hours & hours of reading and shouldn't take much battery at all, since you are just reading text.

dim your screen as much as you can. I've been surprised at how much battery life this has saved me.

I had a long spell with Flood-it, so, fwiw, here's my personal list of high-engagement, low-energy games, all of which have (to varying degrees) withstood the test of time: - https://itunes.apple.com/it/app/edge/id300896018?mt=8 - https://itunes.apple.com/it/app/monospace/id302367044?mt=8 - https://itunes.apple.com/it/app/chromixa/id335480027?mt=8 - https://itunes.apple.com/it/app/ancient-frog/id304574714?mt=8 - https://itunes.apple.com/it/app/zen-bound-2-universal/id363308208?mt=8 - https://itunes.apple.com/it/app/spider-segreto-di-bryce-manor/id325954996?mt=8 - https://itunes.apple.com/it/app/async-corp./id444539599?mt=8 - https://itunes.apple.com/it/app/mysticalcolors/id352263594?mt=8 - https://itunes.apple.com/it/app/flowerz/id315608188?mt=8 perhaps slightly more power-hungry (tho' it's hard to tell): - https://itunes.apple.com/it/app/eliss/id306950009?mt=8 - https://itunes.apple.com/it/app/osmos/id382991304?mt=8 Another favourite was http://www.slapapp.com/tipoli/, but I gather it's now defunct.

You may not need to worry about draining your battery. A lot of airplanes do have a means of charging your phone. I've been on planes with 110v outlets (Virgin America) and others with USB sockets. http://www.seatguru.com/ may have what's available on your flights.

Carcassone? I play on iPod touch fourth hen, not noticing drain on battery

Word welder isn't free but it's a pretty good word game that isn't too flashy. I can't say I've ever paid too much attention to its battery use, though. Spelltower is another good (but not free) word game. I always keep going back to sol free solitaire for mindless time-occupying. I could play Yukon solitaire for ages (I probably have already).

I can tell you what game NOT to get, even though it's pretty good: flight control saps battery like there is no tomorrow.

My favourite puzzle game is https://itunes.apple.com/us/app/blockwick/id471335098?mt=8 which is low battery use. There is also now a sequel to Flow Free - https://itunes.apple.com/us/app/flow-free-bridges/id569322760?mt=8. Neither are free though.