Ngress be played on Kindle Fire

Define an easy way, I know some people who just sign up for an invite at Niantic Labs and got their invite. As far as I know they constantly send new invites through several channels, and as the game gets massive, I guess the number of sing up invites sent will only get bigger.

It is also a lot of fun to make a fuzz :)

Update: There are several ways to get an invite to ingress:

1. Promote ingress in G+ or your personal blog (make it creative and fun), send a link to +Niantic Project and +Brandon Badger - this method worked pretty well before
2. Follow ingress and niantic labs twitter, e.g. @IngressNews, they give out invites regularly, sometimes they make trivia contests in irc, or refer to other sources like podcasts where some invites are given away - a fast way to get an invite but quite unreliable (you have to win the contest)
3. Sign up for an invite at Niantic Labs
4. Have a friend at google or niantic lab

You can create bigger fields around smaller one (until the links do not cross). The MU will also be credited twice (even with fields belonging to different factions)

According to this documentation:

If one control region fully encloses another control region, both regions get credit for all the mind units they enclose.

Edit :

Rules about links and fields :

• links cannot cross, never : It would be bad. (Dr E. Spengler ;) ) (neither a green link can cross a blue link).
• you can create fields inside other fields, but only if you link some portals making the outer field to an inner portal (source). You can't make a field completely inside another...Yet you can make fields completely around other fields.