As long as I have my private keys...?

[DrBitcoin]

I'm using Jaxx. If you dig into settings you can get a list of all your public and private keys for all your wallets.

I want a point blank "yes" or "no" answer.

If I save these private keys to all my bitcoin and altcoin wallets, and the app stops working, crashes, becomes abandon ware...do I still have access to all my coins?

[TryNinja]

Yes.

You just need to import your Bitcoin private key or seed phrase in another wallet and you are good to go.

[HI-TEC99]

The best thing you can do is backup your Jaxx wallet's seed words. Jaxx uses a system where it can generate an almost limitless number of addresses (and private keys) from its seed words. If you only back up the private keys your wallet currently contains it may generate more, then crash. You risk losing coins in that situation if you didn't back up the seed words.

If you have the seed words for Bitcoin addresses you can import them into an alternative wallet like mycelium which will restore access to your coins. I advised someone who had a malfunctioning Jaxx wallet to try importing into mycelium some time ago and it worked. You can read about it here.

Try importing your jaxx wallet's seed into mycelium's android wallet and see if your coins show up in it. According to this post the two wallets can use each others seed.

https://www.reddit.com/r/BitcoinBeginners/comments/5xt8m6/my_12_word_seed_from_jaxx_isnt_showing_my_balance/

Jaxx follows BIP 32/39/44, so Copay (mobile and desktop) and Mycelium (Android, probably iOS) can restore the Bitcoin wallet from Jaxx.

^^ This worked! Thank you so much!

[DrBitcoin]

The best thing you can do is backup your Jaxx wallet's seed words. Jaxx uses a system where it can generate an almost limitless number of addresses (and private keys) from its seed words. If you only back up the private keys your wallet currently contains it may generate more, then crash. You risk losing coins in that situation if you didn't back up the seed words.

If you have the seed words for Bitcoin addresses you can import them into an alternative wallet like mycelium which will restore access to your coins. I advised someone who had a malfunctioning Jaxx wallet to try importing into mycelium some time ago and it worked. You can read about it here.

Try importing your jaxx wallet's seed into mycelium's android wallet and see if your coins show up in it. According to this post the two wallets can use each others seed.

https://www.reddit.com/r/BitcoinBeginners/comments/5xt8m6/my_12_word_seed_from_jaxx_isnt_showing_my_balance/

Jaxx follows BIP 32/39/44, so Copay (mobile and desktop) and Mycelium (Android, probably iOS) can restore the Bitcoin wallet from Jaxx.

^^ This worked! Thank you so much!

 And the Seed phrase is that random string of words that it tells you you must remember and don't give to anyone? If I have that, then I can use any wallet?

[DrBitcoin]

The best thing you can do is backup your Jaxx wallet's seed words. Jaxx uses a system where it can generate an almost limitless number of addresses (and private keys) from its seed words. If you only back up the private keys your wallet currently contains it may generate more, then crash. You risk losing coins in that situation if you didn't back up the seed words.

If you have the seed words for Bitcoin addresses you can import them into an alternative wallet like mycelium which will restore access to your coins. I advised someone who had a malfunctioning Jaxx wallet to try importing into mycelium some time ago and it worked. You can read about it here.

Try importing your jaxx wallet's seed into mycelium's android wallet and see if your coins show up in it. According to this post the two wallets can use each others seed.

https://www.reddit.com/r/BitcoinBeginners/comments/5xt8m6/my_12_word_seed_from_jaxx_isnt_showing_my_balance/

Jaxx follows BIP 32/39/44, so Copay (mobile and desktop) and Mycelium (Android, probably iOS) can restore the Bitcoin wallet from Jaxx.

^^ This worked! Thank you so much!

 And the Seed phrase is that random string of words that it tells you you must remember and don't give to anyone? If I have that, then I can use any wallet?

 Also that seed word phrase would also work for altcoins not just Bitcoin's right ?

[HI-TEC99]

The best thing you can do is backup your Jaxx wallet's seed words. Jaxx uses a system where it can generate an almost limitless number of addresses (and private keys) from its seed words. If you only back up the private keys your wallet currently contains it may generate more, then crash. You risk losing coins in that situation if you didn't back up the seed words.

If you have the seed words for Bitcoin addresses you can import them into an alternative wallet like mycelium which will restore access to your coins. I advised someone who had a malfunctioning Jaxx wallet to try importing into mycelium some time ago and it worked. You can read about it here.

Try importing your jaxx wallet's seed into mycelium's android wallet and see if your coins show up in it. According to this post the two wallets can use each others seed.

https://www.reddit.com/r/BitcoinBeginners/comments/5xt8m6/my_12_word_seed_from_jaxx_isnt_showing_my_balance/

Jaxx follows BIP 32/39/44, so Copay (mobile and desktop) and Mycelium (Android, probably iOS) can restore the Bitcoin wallet from Jaxx.

^^ This worked! Thank you so much!

 And the Seed phrase is that random string of words that it tells you you must remember and don't give to anyone? If I have that, then I can use any wallet?

 Also that seed word phrase would also work for altcoins not just Bitcoin's right ?

It will work for altcoins if you can find a wallet for every supported altcoin that can import Jaxx seed words. I haven't used Jaxx and don't know all the altcoins it supports. There could well be some altcoins that can't import Jaxx seed words, in which case you are best backing up the private keys too.

This quote says jaxx automatically switches address every so often. If that's true, and it switches to newly generated addresses, you might be continually backing up new private keys.

https://forum.z.cash/t/restore-t-adress-jaxx-wallet-warning/8225/34

Don´t worry about the changed address. The address changes automatically at certain time intervals. Nevertheless, any previous address is still valid and can still be used.
I have just looked in my wallet: I am also missing some coins. But that´s not because the change of your adress. Jaxx currently must have a problem when retrieving the blockchain, so not all coins will be displayed. You can simply enter your t-address at Zchain11 and then you can see that all your coins are still there. Hopefully, Jaxx fixes the problem quickly!

To be safe make sure you back up an altcoin addresses private key before sending coins to it.