Webscorer supports the following readers for NFC and RFID passive & active chip timing:

ACS ACR122U (USB NFC)
ACS ACR1552 (USB NFC)
ACS ACR1255U-J1 (USB NFC)
ACS ACR1555U (USB NFC)
Alien Technology ALR-F800
Alien Technology ALR-9900+
Any RFID reader with LLRP
Bluetooth Beacon
Bluetooth RFID (any HID device)
Chainway C5P
Emit ETS1 / ETS2 via TCP/IP
Emit ETS1 / ETS2 via USB
Feibot A400
Feibot F800
Feibot F860
Feibot F2000
Feibot U488
Impinj R120
Impinj R220
Impinj R420
Impinj R700
Impinj R1000
Invelion YR3000
Invelion YR8700
Invelion YR8900
Motorola / Zebra FX7400
Motorola / Zebra FX7500
Motorola / Zebra FX9500
Motorola / Zebra FX9600
Motorola / Zebra FXR90
MyLaps BibTag Decoder
MyLaps ProChip Decoder
NFC (phone as reader)
Nordic ID AR62
Nordic ID AR82
Nordic ID AR85
Nordic ID Sampo S2
Race Result Decoder 5000
Race Result Ubidium
Race Result USB Timing Box
Radiant Sensors RSWR-400
RFID Timing Systems Joey
RFID Timing Systems Echo
RFID Timing Systems Ultra 4
RFID Timing Systems Ultra 8
SPORTident (BSM7/8 or SRR)
Thinkify TR-265 USB
ThingMagic Astra
ThingMagic Izar
ThingMagic M6
ThingMagic Sargas
ThingMagic USB Pro

If you have a reader that's not listed above, you’ll want to check from the manufacturer’s specs that the specific model includes support for the LLRP (Low-Level Reader Protocol) which is how the Webscorer app communicates with the RFID reader.  The LLRP protocol was invented in 2008, and adopted by the leading RFID vendors in the years following, so older RFID reader models may need a firmware upgrade to support it.  The support for Emit, Feibot, Invelion, MyLaps, Race Result, RFID Timing Systems and Thinkify readers is implemented with their respective (proprietary) protocols. 

Any handheld Bluetooth RFID reader that's capable of acting as an HID device (emulating a Bluetooth keyboard) can be used with Webscorer PRO.  ACS readers support NFC chip timing.

The active chip timing systems (wire loop antenna & chips with a battery) supported are Emit, Feibot, MyLaps and Race Result.

Note that Webscorer PRO gets the chip data directly from the reader in real time - using a direct wire-level protocol to communicate with the reader.  This is in contrast to most "scoring software" that create results from raw chip data files generated by a separate "timing software" that feeds the files the scoring software in semi-real time during the race or after the race is over.  Hence Webscorer PRO can be thought of as a combined timing and scoring software which has the obvious benefits for getting real-time results, posted on a big screen or on a website while the race is underway via the "Live results" feature.   And allows the timing data to be monitored / corrected as it happens.