Wifi Prioritizer is a Wi-Fi mangement utility that allows you to specify the order in which your device will attempt to connect to different access points, if more than one familiar access point is available.

Mileage Varies, Priority Won't

The app allows you to set a custom list of access point priorities based on those you've already connected to previously. The primary issue with Wifi Prioritizer's implementation of things is that you cannot, for example, have the app take into account signal strength. If you know that you're going to be in a place where your highest-priority access point is at 90%, this is fine, but if you go somewhere that a lower-priority access point is stronger, you will need to either change the app's settings on the fly or turn it off.

Functional, If You Need It

Wifi Prioritizer is largely useful if you are in a familiar area and staying in a familiar spot or spots, since it can prevent your device from connecting to a less desirable access point first (like one that requires connecting through a portal). It's less useful if you're travel a lot and encounter new Wi-Fi access points, or if you move a lot within an access point's range.