This is a nice-ordered class (tools) that will help you to do A LOT of things more easy (validating, working with dates, detecting spam, and so..)
The documentation is very complete, there I explain how each function works and each one has a example perfectly Syntax-Highlighted. Plus, have some examples in /examples/ folder.

Here is what you can do with this class:

1. Validate numeric values (strict and non-strict)
2. Validate only-letters
3. Check if a string contains X thing (word, phrase, letter..)
4. Check if a string is utf-8
5. Get Biggest or Smaller value in an array
6. Check if a number is between other two
7. Validate Email
8. Validate Telephone
9. Validate Zip Code
10. Validate Hexadecimal
11. Validate IPv4
12. Validate FileSize
13. Validate Card Number (credit/debit)
14. Get company card by number (VISA, MasterCard,…)
15. Validate name, date, regexp
16. Get number of coincidences of a RegExp
17. Get RegExp values in two different ordered ways
18. Parse number (Example: 10000 will return 10,000)
19. Get how many times a word appears in a string
20. Convert to Upper/Down a string
21. Replace an array of words in a string
22. Parse UNIX date
23. Clean SQL or HTML, allowing to declare exceptions to not be cleaned
24. Get seconds of difference between two dates
25. Add seconds to a date
26. Extend a date (Get years, months, days, hours, minutes, seconds) in a string or array
27. Comes with a list of blocked words (for preventing spam). You can temporaly or permanently add more words
28. You can replace blocked words with what you want
29. You can count or get blocked words found in a string

Rating will be really appreciated.
Questions? Suggestions? Please, don’t doubt to leave a comment!