Why not adopt me?
Perl::Tags::Naive
A naive implementation. That is to say, it's based on the classic pltags.pl script distributed with Perl, which is by and large a better bet than the results produced by ctags. But a "better" approach may be to integrate this with PPI.
Subclassing
See TodoTagger in the t/ directory of the distribution for a fully working example (tested in <t/02_subclass.t>). You may want to reuse parsers in the ::Naive package, or use all of the existing parsers and add your own.
package My::Tagger;
use Perl::Tags;
use parent 'Perl::Tags::Naive';
sub get_parsers {
    my $self = shift;
    return (
        $self->can('todo_line'),     # a new parser
        $self->SUPER::get_parsers(), # all ::Naive's parsers
        # or maybe...
        $self->can('variable'),      # one of ::Naive's parsers
    );
}
sub todo_line { 
    # your new parser code here!
}
sub package_line {
    # override one of ::Naive's parsers
}
Because ::Naive uses can('parser') instead of \&parser, you can just override a particular parser by redefining in the subclass.
get_tags_for_file
::Naive uses a simple line-by-line analysis of Perl code, comparing each line against an array of parsers returned by the get_parsers method.
The first of these parsers that matches (if any) will return the tag/control to be registred by the tagger.
get_parsers
The following parsers are defined by this module.
trim- 
A filter rather than a parser, removes whitespace and comments.
 variable- 
Tags definitions of
my,our, andlocalvariables.Returns a Perl::Tags::Tag::Var if found
 package_line- 
Parse a package declaration, returning a Perl::Tags::Tag::Package if found.
 sub_line- 
Parse the declaration of a subroutine, returning a Perl::Tags::Tag::Sub if found.
 use_constant- 
Parse a use constant directive
 use_line- 
Parse a use, require, and also a use_ok line (from Test::More). Uses a dummy tag (Perl::Tags::Tag::Recurse to do so).
 label_line- 
Parse label declaration