A/B Buddy vs Wi

If you're planning to run an experiment – either on the web or in real-life – it's critical to collect the right amount data so that you know the experiment results are scientifically valid. A/B Buddy is a sample-size calculator that helps you design A/B experiments with a quick slide of a finger. It uses a power-analysis formula to tell you exactly how many subjects, or users, that you'll need in an experiment in order to detect a statistically significant difference between two groups. Because if you have too few users in the experiment, you'll never see any difference between "A" and "B"; if you have too many enrolled, the experiment will never end. A/B Buddy tells you exactly the right number. How does it work? Let's say your current conversion rate is 10%, and you want to see if a proposed change from the design team can boost that number up to 12% – that is, a 20% lift in the conversion rate. Simply pop open A/B Buddy, set the Baseline conversion rate to 10%, and the Minimum Detectable Effect to 20%, and your answer is waiting for you at the top of the screen. A/B Buddy includes a Share button, which links to a web page displaying your sample size calculation. Your numbers, however, remain 100% private – all the information is stored in the URL fragment, and is never transmitted to any servers. By default, A/B Buddy uses the most common statistical thresholds: 5% for the significance level (false-positive rate), and 80% for the power level (ability to detect the Minimum Detectable Effect). Power users can adjust these values after unlocking the Pro Features in-app purchase. But most users will find the defaults adequate for their needs. Questions? Suggestions? Ideas? Feedback is always welcome at emmiller@gmail.com

Find the places where your connection works better. Walk around with your iPhone and compare Wi-Fi or mobile connectivity along a colored 3D trail in the camera view. The color changes continuously as measurements update. Pause whenever you need to; the recorded trail stays until you clear it or change networks. For Wi-Fi, the app checks replies from the local router: latency, unanswered requests and jitter. For mobile data, it combines the iOS connection-quality estimate, when available, with small internet probes to Cloudflare, approximately once per second. You can choose Auto, Wi-Fi or Mobile network. Internet latency is not radio signal strength. The app does not measure download speed, locate a router or cell tower, or measure your distance to one. Gray sections mean there is no recent measurement. A router may block ping, so unanswered requests alone do not prove weak reception. Free, with no ads, in-app purchases or account. Camera images and the room map are processed on your iPhone; the app does not record photos or video or send room data to the developer. In mobile mode, Cloudflare receives your source IP address through the probes. Camera and local-network access are required. Location permission is optional and only used to show the Wi-Fi name. Requires an ARKit-compatible iPhone with iOS 17 or later.