ASO Tools
AppAnnie - https://www.appannie.com/
Sensortower - https://sensortower.com/
Apptweak - https://www.apptweak.com/
Appnique - http://appnique.com/
Appmind - http://appmind.co/
Keyword Ranking Services
AppRank PRO - https://apprankpro.com/
Keenmobi - https://keenmobi.com/keyword-installs/
Mopeak - https://mopeak.com/buy-keyword-installs/
Buy graphics for games:
Graphicriver - http://graphicriver.net/
Photoeditoronlinefree - http://www.photoeditoronlinefree.com/
Gimp - http://www.gimp.org/
Inkscape - https://inkscape.org/en/
Paint.NET - http://www.getpaint.net/index.html
Buy music for games:
Looperman - http://www.looperman.com/
Partnersinrhyme - http://www.partnersinrhyme.com/pir/free_music_loops.shtml
Freesound - http://www.freesound.org/
Audiojungle - http://audiojungle.net/
Freemusicarchive - http://freemusicarchive.org/
App UI Designs:
Pttrns - http://pttrns.com/
Mobile-patterns - http://www.mobile-patterns.com/
Inspired - http://inspired-ui.com/
Mobilemozaic - http://www.mobilemozaic.com/
Lovelyui - http://www.lovelyui.com/
App localization
Icanlocalize - http://www.icanlocalize.com/site/
Onehourtranslation - https://www.onehourtranslation.com/
Localizedirect - https://localizedirect.com/storefront/
Ulatus - https://www.ulatus.com/
Locteam - http://www.locteam.com/
Oneskyapp - http://www.oneskyapp.com/
Note : we will update this page with useful resources regularly.