It was just a question of time when Adobe will release some kind of photo editing software for mobile phones and in March of 2013 the Adobe Photoshop Express was released. (https://play.google.com/store/apps/details?id=com.adobe.psmobile) Since that most of the modern mobile phones have really good cameras, the first release was a big bust, it was not really good and nobody really liked it. So Adobe provided the super-duper version, Adobe Photoshop Touch, a really top of the line photo editing software primarily for tablets, but with phone display sizes of five inches and above, this limitation is not really an issue. (https://play.google.com/store/apps/details?id=air.com.adobe.pstouch) It is not free, but you really get Photoshop quality editing and that is really something.
Viber by Viber Media Inc. is pretty similar to Skype. The best thing about Viber is that it is not owned by Microsoft. Other than that, there are more than 200 million users of Viber and most people have it already installed on their mobile phones. You can call all your friends directly, using 3G, but you can also use Wi-Fi, which makes it really cheap to phone a friend who is nowhere near your location. International calls and roaming are expensive, but if you can Viber with them, then you pay nothing extra. Naturally you can communicate with Viber installs on desktops, Windows and Mac are supported. Additionally, groups with 40 participants can join an online conference. Texting, stickers, emoticons, photos, videos, anything goes. This is an awesome app that you really need to check out.
If you want to edit and view all kind of Microsoft Office documents, .pdf files and some more, then you need the Polaris Office. Available per Aptoide, (http://android777.store.aptoide.com/app/market/com.infraware.polarisoffice5/50331010/4221599/POLARIS%20Office%205) you can use this app to do some editing and view files, including PowerPoint presentations on your mobile device. If you are on the go and just need to fix up a file, but do not have access to your computer, this app will rescue the day.