Right now I'm storing every thing on coinbase, but will probably start using bitflyer instead when it opens some time very soon in the USA (supposed to open in USA in 2017 autumn).. However, I don't want to keep my coins in those types of wallets, because I was one of the people who got their coins stolen by mt.gox (I only had 1 bitcoin at that time), and so I don't want the same thing to happen again.. Keeping your coins in an exchange like that means that either 1: the exchange could be evil again and steal your coins; 2: Their system could get hacked and some one steals lots of peoples' coins; 3: the government could force the exchange to give them your coins.. So that is why I want to move them in to just a normal personal wallet on an air-gapped computer (maybe a raspberrypi running raspbian for the OS or some thing).. At that point, I will only be using exchanges to buy coins, and then moving the coins straight to my personal wallet.. If I want to sell off some coins, I just do the reverse (personal wallet > exchange > fiat currency > my credit-union/bank account)..

I suppose I will end up using the normal bitcoin-qt client for the personal wallet on the air-gapped computer.. And I need to find the equivalent clients for litecoin and ethereum as well..
I actually don't have a cell-phone, so I wouldn't even know which cell-phone apps to use, but not sure I would trust putting any sort of wallet password in to a phone any way, unless I had sent a small amount of coins to a seperate wallet just to pay for some small things..

Right now the coins I have are just all the ones that coinbase offers (which is only 3 right now: bitcoin, litecoin, ethereum), although they are going to add bitcoin-cash on 2018 january 01.. By that time I will probably be using bitflyer exchange to buy coins instead, mainly because I think they will have more coins to choose from.. kraken also has more coins to buy than coinbase, but I had a lot of buggy glitches and other problems when I tried to use kraken.. I will probably just end up buying/holding any coin that bitflyer offers, because I am investing in the whole crypto-currency sector in general, not just one coin.. Bitcoin won't stay the king for eternity..

What I do is, every month I calculate the profit (not the entire total that you have in there) that was made during the month, and then multiply it by 0.09 (which gives you 9%), and I convert that 9% in to fiat currency and send it to my credit union as my kind of "monthly allowance".. (I initially used 10%, but my OCD wants to compensate for the fees that the exchange charges to convert money back and forth from fiat<->crypto, so I make it 9% instead)..

So if you have like $5000 worth of coins, and in a month the value goes up by about 30%, then you now have $6500.. So your profit you made that month is $1500.. So decimate that profit (1500) by 0.09 (9%), and you get $135.. So I convert (sell) $135 worth of coins in to fiat, and send it to my credit union.. (I usually just take it out of which ever coin has the highest dollar amount in my wallet, because if you take it out of all of your coins equally, you end up paying conversion fees on every coin type)..

You keep the other 90% of the profit in there, so that it makes even more profit next month.. You COULD take the whole $1500 out, but you would be ripping your future self off big time when you calculate how much your stash accumulates to over the next several months/years.. If you really want more money now, you could bump the monthly-allowance percentage up to like...24% or some thing...I don't think I would go higher than that.. And even though your allowance that you grant your self starts out meager, just remember that every month that allowance will (should any way) get bigger each month..

I want to touch quickly on the reason WHY crypto-currencies keep going up and never down.. It is simply because they are hugely under-valued.. The entire world is only now realizing what this disruptive emerging technology is, and eventually they will realize that fiat currency is now obsolete.. Basically, they don't realize how much crypto-currencies are worth, and the market reflects this.. So basically you are buying these coins at a huge discount, and as people slowly realize what crypto-currencies actually mean, the value/price rises.. The value also rises as more places adopt and accept crypto-currencies and as they become more common-place..
You can also see this in the fact that hardly any one (except very stupid investors) are willing to short these crypto-currencies.. The market to short bitcoin (and other crypto-currencies) exists, but is very shallow.. It is because most every one can see that crypto-currencies are here to stay; and it is already starting to do the job it was created for: Giving the power of money back to the normal people..

By the way, storing coins in a personal wallet has its own risks obviously.. Maybe your exchange can't steal them, but if you lose your private key to the wallet some how, your coins are gone.. What you might do is use a very secure computer (maybe air-gapped) to make some text file with all your sensitive information, like wallet addresses their private keys, and then encrypt it using some thing like scrypt.. On linux you can type some thing like: scrypt enc -t 480 info.txt info.txt.sc
That would encrypt info.txt in to info.txt.sc, and it would take 480 seconds (8 minutes) for each guess.. Meaning you personally would have to sit there for 8 minutes to decrypt the file, but an attacker would also have to wait 8 minutes just for 1 guess.. You shouldn't have to access this file very often any way.. The reason scrypt is good is because it requires lots of memory to encrypt/decrypt, so an attacker with a super computer would also need lots of memory to attack the file very quickly.. You could also double or triple encrypt it with different things if you want to..
An other strategy might be to split your stash in half, keeping one in the exchange and one half in a personal wallet, so that way if you lose your personal wallet some how, you still have half your stash.. Or if the exchange steal your coins, you still have the half in your personal wallet..