Keeping in mind that the free information on the Internet is worth every penny you paid for it, I've made the following utilities available which I wrote for myself but which others sometimes ask to use. I can't promise they're appropriate for you, but I do sometimes modify them in response to feedback from others.

The Cataloging Calculator

Cataloging tool that finds variable and fixed MARC fields (bibliographic and authority data), LC subject headings, language codes, geographic area codes, publication country codes, and AACR2 abbreviations, LC main entry and geographic Cutter numbers.

The SIM Tool

Tool that allows quick lookups of SNOMED, ICD-10, and MeSH headings

Raffle

Paste a bunch of names into a box, and it flips through them on the screen at 10 per second and picks a winner

Countdown Timer

Designed to keep speakers on track, the large text is highly visible. When there are two minutes left, the text turns bright red, at one minute, it starts clicking off tenths of a second to instill a sense of urgency, and the screen flashes for the last 30 seconds to let people know they need to wrap it up. Highly effective.