Vanhail and I are a bit of an odd team so I thought I'd jot down a little bit of our process for you dudes, might be helpful. Who knows.
First a little background. We have been working part time on Warbits for about 2 years. We live in two different states (Texas and Massachusetts). We have never met in person. Our wives have not left us yet.
Whew!
First: We communicate CONSTANTLY via Google Hangouts (was gChat) and we have fairly regular video and voice calls.
Second: Dropbox! Our entire project lives in a shared Dropbox folder and I don't think we could function without it.
So I do almost all my work in Adobe Illustrator. I think I started using it because I needed assets that I could easily scale and export at different resolutions because of different device capabilities. Right now we support the iPhone 3GS/iPad 1 up to current retina devices.
Each asset has 3 versions, SD, HD, and iPad HD. SD is used for the 3GS, HD is used for retina iPhones and non retina iPads and iPad HD is used for the new retina iPads.
Newer versions of illustrator will allow you to have up to 100 multiple art boards which can be great for sprites, tilesets, and mockups.
This means I can have a bunch of sprite frames in one document and export a bunch of PNGs all at once.
For example this is what the red gunner Illustrator file looks like. Every unit has file setup exactly the same.
When I'm designing a new unit or animation I constantly export the PNGs and open them in Photoshop to preview it as a GIF.
Adobe Bridge has a great feature that will let you select multiple images and open them as layers in photoshop.
When I'm happy with the result I run an action to export all those frames to a dropbox folder at all the different resolutions. Once all the units and colors have been exported Vanhail uses TexturePacker to compile all the sprites into one sheet so it can be used in game.
So I hope this post was interesting in some way. Here have a full res iPhone 5 screenshot!
Let me know if you have any questions/suggestions/whatever