Storing private key in apps and softwares that are local Im new to butcoin. I installed an app in my phone called Bread. And another in my computer called Electrum.

Both of them generated a seed(12 words) for me and it seems that seeed is my private key in the bitcoin network.

My question is: these softwares has my private key and i dont know if they stored it in remote servers. This means someone other has my private key and can access my money? This is a safe way in bitcoin culture? They are really local?

I want to use safest way to work with bitcoin and i dont want store my info in any website or app that can access my account, delete my account or any other intervention.

For safest way should i have my own copy of public ledger in a personal server? What is the safest way?
BreadWallet &amp; Seed: the seed is not your private key, it is used to generate the private key, and it is stored locally on your phone. However, the level of trust in me (or anyone else) is not sufficient, when saying this. You might want to do a source code review by yourself to be 100% sure. In general I use Bread as well, for daily usage, not for big amounts. It is a fairly well working wallet, and the value in it is comparable to the wallet with FIAT money. There are privacy issues with such wallets like BREAD (they are called SPV wallet), and the risk with these SPV wallets is, you trust someone else that they verify the bitcoin blockchain correctly. E.g. there was the risk to fall victim of the segwit2x fork, and then you would think you are on the original bitcoin, but in fact the provider (and all SPV wallets) would be on a new blockchain, which has changed parameters. So with SPV wallets, only use small amounts of money. 

Electrum: this is similiar, the seed is used to generate the privkeys. Electrum is also an SPV type of wallet, and you trust the provider's blockchain. I am not sure about the possibility of code review though. 

Wanting to be 100% secure and safe, you need to run a full node (aka bitcoin core client or similiar), and get used to the idea of cold storage. There is lots of links to cold storage here in the forum.