Usage with Laravel:
{{-- Basic input addon --}}
{!! Former::open()->method('GET') !!}
    {!! Former::text('test2')->append('€') !!}
{!! Former::close() !!}

{{-- Multiple input addons --}}
{!! Former::open()->method('GET') !!}
    {!! Former::text('test3')->append(['€', 'second']) !!}
{!! Former::close() !!}

{{-- Button addon --}}
{!! Former::open()->method('GET') !!}
{!! Former::text('test4')->append('<button class="btn">OK</button>')
!!}
{!! Former::close() !!}

{{-- Button addons --}}
{!! Former::open()->method('GET') !!}
{!! Former::text('test5')->append(['<button
class="btn">OK</button>', '<button class="btn">2</button>']) !!}
{!! Former::close() !!}

Credits: @mrextreme

Reference:
formers#581 (comment)