I was also stolen from the same app
When I spoke of support, this was their response
Hello,
We cannot really pay out any compensation legally, because there's no legal case.
As a company bond by law, we cannot possibly do it.
However we can grant you a lifetime PRO subscription. This is the least we could do for you. I'm very sorry.
Yes, they are procrastinating on us

Related to security issues in your app or OP simply getting his API keys compromised by something that was his entirely responsibility (e.g malware in his device, phishing, etc...). I'm not trying to spread any FUD, but if there is any possibility of your app being vulnerable in anyway, you need to disclose it.

I myself have used your app for quite some time and only stopped recently because you do not support my favorite local exchange, but I still have the app installed in my phone. I don't want to risky anything because of a possible issue on your part. =/

Now, if the issue is on your hands, OP, I can't see why TabTrader would return anything to you. Electrum or Bitcoin Core don't reimburse people if they get hacked or download a fake wallet.

We are 100% with you.
We really are sorry that you lost some of your funds.
We are trying to find what happened.

Hello respectable brother.
It means that we still doing our investigation.
We are on your case.
There are some preliminary findings which we are trying to confirm.

But like we said if we were hacked and our user data was compromised hundreds of thousand of users would have been here in this thread. But they aren't.

Having access to enough funds on an exchange, one can for an example buy a lot of the same shitcoin which has very low volume, then using the other accounts he places buy orders to buy his bags for a lot higher, they can then make buy orders for the same shitcoin on his main account and then using the other accounts he makes a lot of sell orders so he can buy-back those coins for cheap, and then again sell it for a higher price, rinse and repeat.

Since the hacker/attacker can't withdraw funds, all they do is liquate you to their favor, in other words making 100% winning traders and then withdraw the funds from their main account, one might think that a "reputable" exchange like Bittrex should sense such P&D operations going on and lock all accounts involved, but I don't trust any of these crypto exchanges, you are simply paying for the mistake of using a third-party app that has control over your funds, people think that because these apps can't withdraw money directly from their account - then their funds are safe, which is a misconception.

Also, the fact that no more victims showed up, it's safe to assume the app itself was not hacked and it's more likely that your API keys got compromised somehow. If you are lucky enough then bittrex might have blocked the account/accounts who made those trades and your stolen money is still there, but I would give that a 10% at best case scenario, the 90% scenario is that the funds are long gone, Tabtrader will refuse to compensate you saying it's your fault for not keeping your credentials safe, Bittrex will say those orders were made by an app which you personally gave it the keys to trade for you, and in the end, it's really your mistake for trusting something like Tabtrader or other platforms when you could have simply used the exchange's app itself.
 
Thank you for your smart reply.
Actually, this is what deceived us, which is that the money is wasted by withdrawals only
But the official is the failed application because my phone is highly secure and I do not use the computer

We are helping you identify what happened to your funds.
And yet you go to forums too.

For everyone concerned:
1) This individual is the only one had this issue out of hundreds of thousands of users. If there was an issue in the app, scammers would have used this vulnerablity multiple times. Why scam one person if you could scam all of the users. Just doesn't make sense.

[For full disclosure 2 of his mates also from the same African country reported this issue. Maybe it is the same person just with multiple reports, one in the app, one in email one in telegram, group. Anyway we are talking to all 3 of them in best faith trying to help.]

2) Preliminary investigation showed that this user has compromised his credentials somewhere.

3) But we believe it is unfair to go reporting that such an established and reputable app is a scam without any proof. Moreover we are trying to help him understand what happened the very same moment.

More will unfold later.

It is clear as day that what the member is claiming is that the app pumped and dumped his balance using a low volume coin .
with access to a few accounts you can exactly steal their money without having to withdrawal, i have always warned against the use of trading bots and APIs for this exact reason.