I came across MindJet a few days ago and I am really enjoying it. This app is best used on a tablet. There is a bit of a learning curve to get the hang of it and I am still just learning what all it can do. The main purpose of the app is to take notes and brainstorm ideas into mindmaps (like they used to make us do in school). You can start a map from scratch or use one of their templates. There are different styles, colors and features you can use to customize your maps. You can add attachments, links and additional notes to each 'arm' and you can even add little icons or images to them also. I love making my notes pretty! :o)
Image Source: Google Play
The app is integrated with Dropbox and you can export your MindJet files to Evernote so you can access everything on the go. MindJet also has a task feature to organize all of your to-do's and easily prioritize them. The app allows you to connect with other users in order to delegate tasks to them and share your ideas with them. Mindjet is FREE at Google Play and on iTunes. For more help in using the app, check out the company site at MindJet for tutorials.