Map
The main view. (you can back up to this view from the others)
There are two main modes on the map: placement mode and scoring mode. Toggle mode using (TODO-IMAGE)
In placement mode you can see your location and "free placement"-radius, fountains, placed workers (yours and others), your portals and treasures.
In scoring mode you can see the scoring areas (small, medium or big, depending on your zoom level), a haircross for area selecting and the ranking (TODO IMAGE).
Below the map (white background with small icons): Summary of idle Workers and available Transmitters and also available Portals.
The (TODO IMAGE) loops through your position and your portal positions. If you long press it, you will enable "follow mode" where the map is always centered at your current position. Click again to disable.
Fountains 
On the map you see fountains. They are locations where the crystals flow up to the earth's surface and this is the place to harvest them. You harvest crystals by placing workers on the (click and select place worker) (But you do need Workers, of course)
When fountains are empty they disappear from the map, but don't worry! They will come back after some time. The time depend on their refill speed (keep reading).
The image of the fountains vary in size depending on the current capacity of the fountain. Fountains continuously refill up to their maximum value.
The max value and refill speed vary with the fountain type: 0, 1, and 2. One has higher maximum value but lower refill speed, one has average on both and one low maximum value and high refill speed. (It don't differ that much)
If several players has used the same fountain over a time period they refill faster.
See Fountain
Workers
On the fountains you see placed workers, yours and others. Only workers of the correct color may be placed on them.
See Worker on how to produce and modify workers.
Treasures
TODO Image
See Treasure for information about them