How to use Memabilia
Memability is very simple to use, but there are probably a few things we should say to help you get started.
First off
The first thing is to make sure you get location fixes, which arrive either by GPS or from the cell towers. And to view maps you need a data connection. The amount of data depends on how much you use it, but it can be significant. If you pre-program all your favorite locations using a wifi connection you can use all the other features without needing data. The only twist is that if you're roaming and have data disabled you have to turn off cell tower location in your phone's Settings and use GPS instead. For some reason, cell tower location doesn't work without an Internet connection.
Once you start receiving location fixes the Map button will be enabled. So click it and watch a map appear showing where you are now. You can drag the map around and zoom in and out using the buttons at the bottom of the map.
The next thing is to name your current location. Zoom in to a comfortable level and tap the Edit button. The mode changes so when you next tap you'll be asked to provide a name and optional comment for the exact point you tapped. Give it a name such as "Home" or "Office" or "Golf Club". Whatever makes sense to you. You can add as many locations as you like and delete the ones you don't want. A circle one kilometer wide will appear on the map, centered on the point you tapped.
When you type a note into Memabilia it will be saved with the location it was typed at (if known), allowing you to search for it by location. There's a preset location called Unknown for all notes typed when you're not at a known place, so these can still be found too.
What is a location?
A location is a circular area one kilometer (two thirds of a mile) wide surrounding some point on the Earth's surface. As long as you stay within this area the system will still consider you're at the same place. But when you leave this circle the display will show you back at an unknown location.
A typical town is a lot bigger than this, and you may consider your new location to be essentially the same as the old. So you can create a series of named locations all sharing the same name, and the app will join them together. Your named world will gradually grow to look like a set of overlapping circles on a map, such as in this picture of my own home area:

You can see that my mapped world consists of a number of circles, some overlapping, and each being somewhere I have a particular interest in. Where they do overlap it's usually because they're part of the same town - such as with Menton and Ventimiglia on this map. So I give them the same name, then the app will spot that I've arrived somewhere in the combined area.
When you enter a named location's circle, after about a minute the app will show the name. If you add a note it will be tagged with the name of the current location.
Finding notes
You can search for notes in three ways. Firstly, by a word you know is somewhere in the note. Every word of every note is indexed and the Memabilia will instantly return you the most recent note that contains your chosen word.
Second, by date. Give a range of dates and you'll get the most recent note from that range.
And third, by location. You may remember you typed a note while at a particular place, or you may want to look at all the notes you typed at that place. No problem; it's all there.