Evernote is an application that stores your personal notes. if you have ideas or plans, easily add them on this application that can be accessed from any computer or mobile device, even online (you need just internet access).
You will have an account with username and password and you will write personal notes and organize them as you need. Supports to choose custom font and size, format text, add tables, add attachments. If you want, can make specific notes public available or share with others through email, link, Facebook, Twitter etc.
A big advantage is that you can access you notes from everywhere when you need to remember something or to note an idea that you may forget.
Is synchronizing automatically with your other devices, so if you write a note on Android phone, will be available on Windows or Mac too.
It supports to add audio reminders (alerts) and to save web content (if you find useful content on websites, save content in your Evernote account).