I suggest to create an App for Android (I hate iPhone, but maybe too) that any device can connect to Mikrotik VPN (any type).

Regards.

No need for an extra client.
My Huawei connects using its own (androids) client to my MT Router running L2TP IPSec.

Settings->Wireless & Network->VPN->Add new
I do use IPSec preshared key.

IPSec,ok, but what about SSTP? IPSec is not functional for me, to many ports using, easy to block.

Any prestige router manufacture has its own client, that perfectly connect to their own devices, with a few(default) configuration, why Mikrotik not?

But why? If the router offers standard VPN, you're free to use any client you want.

What do you mean "Standard VPN". No VPN is like any other, you can change a lot of parameters....
And in this moment I can not find a Android client for may SSTP VPN that works...
Is this configuration? Ok, explain it how than...

As client I use OpenVPN and for IKEv2 StrongSwan.

A good solution is if you own the router that is able to provide VPN connections to isu that. This to have VPN for all devices connected to that router.

OpenVPN is a bit of a Unicorn with Mikrotik however IKEv2 is in Beta supported. Works well and I get 150Mbits on a 760iGS. I was looking to upgrade to a 4011 but having two 760iGS I build that up and plit the tasks.