A monitoring app cannot tell you whether a husband is cheating, and secretly entering accounts, recording conversations, or attaching a tracker can create serious privacy and legal problems. Start with information you already have a right to see: your own messages, jointly addressed bills, shared calendar entries, and statements from accounts that are legally in your name.
Ask a direct question and describe the behavior that caused concern without presenting guesses as facts. If both adults choose voluntary location sharing for a limited period, use a visible built-in tool such as Find My or Google Maps. Scannero can be used for a consent-based location request because the recipient must open the request before sharing. It is not a covert evidence tool. Buy Scannero →
Keep a dated note of your own conversations if that helps you remember events, but do not copy private messages or publish accusations. For decisions involving separation, finances, children, or safety, a licensed counselor or qualified lawyer is more useful than surveillance software.