Take notes, track your to do list, and save pictures to Evernote. You won’t have to worry about where you saved that note because Evernote synchs across multiple devices, including Android tablets and iPad. Evernote has free and premium versions. For $5.00/month or $45/year you can get up to 1GB of monthly uploads, offline access to your notebooks, collaborative editing and versioning of notes: See here for iPad version and here for the Android edition.