Android: Want a reminder note every time you look at your smartphone? ReNotify lets you add persistent notes to your Notifications pane which won't go away when you tap the 'Dismiss All Notifications' icon. Fire up ReNotify, create a note, check the box for "Persistent" and it will stay there. You can't swipe it away. The only way to dismiss it is to tap the note and then choose Delete. You could even save a note for future use, or restore all your notes at any time. It's especially useful if you want a reminder not to overeat when you head out to lunch, to pick something up on the commute home or to make an important call and you don't want to risk forgetting.
If you don't want the ReNotify icon on your home screen, add it as a shortcut in your Notifications to launch it quickly. The free version is limited to this, but the Pro version adds multi-line notifications, periodic vibrations till you dismiss the note and Android Wear integration.
ReNotify (Free | $1.88 for Pro) [Google Play Store]