wi fi - Automatically switch to a saved wireless access point with the strongest signal

I have a wireless router (D-Link) in room A and a repeater (TP-Link WA750RE) in room B, both having the same SSID. Sometimes, when I go to room B and back into room A, my Nexus 5 (Android version 4.4.3) doesn't switch to the router although it has a stronger signal. It stays connected to the repeater instead.

^{The "Tplink" and "Dlink" are only aliases. Both actually have the same SSID.}

When I switch the Wi-Fi off and on again, it connects to the router. which provides much better speed.

How can I force Android to always switch to the strongest signal? Is there a setting for it, or an app?