I recommend the FX Chronograph. Mine is very fickle and will eat batteries if not removed between use (I have a pack of rechargeable AAA's in the FX Chrony bag). HOWEVER, it is accurate and does a good job. Care must be taken to select the correct pellet weight and speed (not intuitive, good luck) within the REQUIRED Android or Apple app.
I prefer the Caldwell chronograph but it is another bag to carry. The FX Chronograph fits inside my existing range bag and weighs a few ounces. They can be had for around $200. If not available then I suggest the Caldwell model because of ease of use and quality of the product and needed Android or Apple app.